STOP I. R. C. Shearman, A. J. Turgeon, J. B. Beard and J. M. Vargas

Transcription

1 STOP I R. C. Shearman, A. J. Turgeon, J. B. Beard and J. M. Vargas Symptoms and Correction of Turfgrass Injury from Gasoline, Oil, Kerosene and Hydraulic Fluids. Turfgrass injury sometimes occurs following unintended applications of various materials. The ability to quickly determine the specific cause of turfgrass injury aids turfmen in taking proper steps to correct such problems. A study was undertaken to accurately characterize the symptomology resulting from applications of gasoline, kerosene, hydraulic fluid and motor oil to a creeping bentgrass (Agrostis palustris Hud6. ) turf. The first three materials were sprayed on at rates of 28, 56 and 112 gallons per acre. The motor oil was applied at the same ratio in an oscillating pattern within each plot. After 1 hour, activated charcoal (DARCO S-51)was applied at 200 lb/a across one-third of each plot, and a surfactant (Aqua-gro) was applied at 16 fl. oz. /1000 sq. ft. across an adjacent section of each plqt. The sequence of observable symptoms was recorded after 1 and 3 days. The effects of activated charcoal and the surfactant on turfgrass injury was also determined. The gasoline-treated turf showed the most striking symptoms immediately following application. The turf turned a dark green color and had a water-soaked appearance similar to that observed for some turfgrass diseases. The dark green color persisted through the second day when it gradually turned brown by the third day after treatment. The extent of turfgrass injury or death appeared to be proportional to the rate of gasoline applied; 112 gallons per acre produced nearly complete kill of the turf while the 28 gallons per acre rate resulted in approximately 10% browning and moderate chlorosis of the remaining turf. Neither activated charcoal nor the surfactant appeared to substantially reduce turfgrass injury from gasoline. The ke rosene-treated turf showed no appreciable injury during the 3-day period following application at the rates applied. The hydraulic fluid produced a bright green turf that gradually turned yellow-green by the third day following application. The extent of permanent turfgrass injury from hydraulic fluid is yet to be determined. Motor oil produced results similar to those from the hydraulic fluid. Neither activated charcoal nor the surfactant appeared to change the nature or extent of turfgrass injury from the 4 treatments. The above investigations are concerned primarily with the effects on above-ground turfgrass shoots. The effects and correction of higher levels of soil contamination by the four materials are also being considered.

2 Bentgrass Variety Evaluations for Greens. Eighteen bentgrass varieties, both seeded and stolonized, were established September 30, They are mowed daily at inch with clippings removed. Split-plot nitrogen application rates of 4 and 7 pounds per 1000 square feet per year are applied across the plots. Toronto, a vegetatively established creeping bentgrass, and Penncross, a seeded creeping bentgrass, have ranked highest in turfgrass quality during the initial two growing seasons (Table 1). These two are followed closely by the seeded European selection known as Emerald and a Michigan State University selection, MSU-28-Ap. Kingston velvet bentgrass, which initially rated quite high in turfgrass quality, is slowly declining due to the invasion of off-type plants. Other bentgrass varieties performing quite acceptably but ranking slightly lower than the previously listed varieties during the initial two years include Pennpar, Cohansey, and two other MSU selections. Ranking below these creeping bentgrasses are a number of colonial bentgrasses including Exeter and Astoria. The older bentgrass varieties established in late fall of 1961 can also be observed immediately east of the new experimental area. The 1961 plantings are to be terminated immediately following the field day. During this ten year evaluation period Toronto, Penncross, and Cohansey creeping bentgrass have ranked as the three best varieties. Of particular interest is the extent of thatch accumulation occurring over the years as well as the relative ability of the individual varieties to prevent the encroachment of off-type bentgrasses that cause an objectionable degree of variability.

3 Table BENTGRASS VARIETY EVALUATIONS FOR GREENS. East Lansing, Michigan Bentgrass (Agrostis) Variety ^Toronto ^Penncross Emerald *MSU-28-Ap Nr Kingston *Pennpar *MSU-18-Ap ^Cohansey *MSU-38-Ap Seaside Exeter Brabantia Astoria Holfior Highland Boral BT 806 Browntop Type creeping creeping creeping velvet creeping creeping creeping creeping creeping colonial colonial colonial colonial colonial colonial colonial Visual Turfgrass Quality Ratings (1 - Best; 9-Poorest)** ^Established vegetatively from stolons, **Average of 6 seasonal ratings.

4 STOP 2 D. P. Martin and J. B. Beard The Comparative Rooting Ability of Transplanted Sods as Affected by the Particular Variety or Blend of Kentucky Bluegrass. The ability of sod to root into the underlying soil after transplanting is an important criteria from the consumer utilization standpoint. A technique was developed at Michigan State University for evaluating sod rooting under field conditions. The Michigan Sod Rooting Test involves placing a harvested 10 inch square sod piece in a wood frame that has a fiber glass screen secured to the bottom. This arrangement is then placed on a recently prepared moist soil and permitted to root into the underlying soil for a specified period of time ranging from 25 to 50 days depending on the objectives of the study. At that time a block and tackle arrangement with a mechanical advantage of five is connected to the four corners of the wood frame containing the rooted sod. A force is then applied at a uniform rate to the sod. The number of pounds required to pull the sod free from the underlying soil is then utilized as a measure of transplant rooting. This technique has previously been utilized in comparing the transplant rooting ability of sod grown on organic and mineral soil. Nine experiments conducted throughout a growing season and a three year study where the sod was lifted 6, 12, 18, and 24 months after transplanting indicated no significant difference in the rooting ability of sods grown on organic versus mineral soil providing the cultural practices during the period of sod production were comparable. The comparative rooting ability of 18 Kentucky bluegrass varieties and 11 blends were evaluated during the 1970 and 1971 growing seasons. Significant, repeatable differences indicate that this technique can be utilized in evaluating the transplant rooting ability of sod. It is apparent from measurements made to date that the rooting ability of a particular variety or blend will vary substantially over a growing season as affected by the severity of disease and the temperature conditions favoring or impairing shoot and root growth. The 18 Kentucky bluegrass varieties were grown on an organic soil at the MSU Muck Experimental Farm. The sods were harvested at a thickness of 0. 5 inch and transplanted onto a moist, sandy loam soil. The experimental area was subsequently irrigated as needed to prevent wilting of the transplanted sods. The comparative rooting ability of the 18 Kentucky bluegrass varieties varied considerably depending on the specific time of year when the sod was transplanted (Table 2). During the May-June period when Helminthosporium leaf spot disease problems are most severe, those Kentucky bluegrass varieties susceptible to this disease lacked adequate sod rooting ability.

5 Varieties ranking superior in rooting ability during this period included Nugget, A-34, Captan, Campus, Belturf, and Pennstar. The comparative rooting ability of many varieties is quite different during the late fall period. At this time varieties such as Delta, Campus, Kenblue, Windsor, Park, Prato and South Dakota Certified exhibit superior sod rooting ability. Evidently these grasses are able to continue root growth longer into the cool temperature periods of late fall than other leaf spot resistant varieties such as Nugget, Pennstar, A-34, Merion, and Fylking. This variation in rooting ability among varieties through a growing season is additional evidence supporting the desirability of using Kentucky bluegrass blends to provide a wider genetic base and range of adaptation. A series of 11 Kentucky bluegrass blends was also evaluated for sod rooting ability at the same two dates as previously reported in the variety tests (Table 3). The range from maximum to minimum among the 11 blends is not as great as previously reported for individual varieties. In addition, the blends as a group ranked higher in sod rooting ability than the individual Kentucky bluegrass varieties. These data further justify the use of Kentucky bluegrass blends.

6 Table 2. COMPARATIVE TRANSPLANT SOD ROOTING ABILITY OF 18 KENTUCKY BLUEGRASS VARIETIES HARVESTED FROM THE SAME PLOT AREAS AT TWO DATES. East Lansing, Michigan Kentucky Michigan Sod Michigan Sod Bluegrass Rooting Test Kentucky Rooting Test Variety or (pounds) Bluegrass (pounds) Selection 11/10/70** Variety 7/2/71*** Delta 67 Nugget 81 Campus 66 A Kenblue 65 Captan 77 Windsor 61 Park 60 Campus 75 Prato 59 Belturf 72 South Dakota Cert. 58 Monopoly 71 Belturf 54 Pennstar 68 Captan 54 Fylking 55 Arboretum 53 Merion 54 Newport 51 Newport 46 Cougar 49 Delta * Monopoly 49 Kenblue * Fylking 48 Windsor * Park * Merion 47 Prato * A South Dakota Cert. * Pennstar 38 Arboretum * Nugget 24 Cougar * *Sod could not be transplanted due to severe Helminthosporium leaf spot thinning. ^Transplanted August 2, ***Transplanted May 18, 1971.

7 rable 3. COMPARATIVE TRANSPLANT SOD ROOTING ABILITY OF ELEVEN KENTUCKY BLUEGRASS BLENDS HARVESTED FROM THE SAME PLOTS AT TWO DATES. East Lansing, Michigan Michigan Sod Rooting Test Percent Composition of 11 Kentucky Bluegrass Blends (Pounds) Merion Newport Park Fylking Windsor Prato 11/10/70* 7/2/71** Ave transplanted September 31, **Transplanted May 18, 1971.

8 STOP 3 J. M. Vargas Bentgrass Variety Evaluations for Fairways and High Quality Lawns. The same 18 bentgrass varieties as previously included in the greens evaluation studies are also utilized in this fairway-high quality lawn evaluation experiment. The experimental area is mowed 3 times per week at a cutting height of 0. 5 inch with clippings removed. Split-plot nitrogen applications at rates of 4 and 7 lbs per 1000 sq. ft. per year are applied across the plots. Although the same varieties, Toronto, Cohansey and Penncross, rank higher in terms of visual surface quality ratings, they have been characterized by problems with excessive thatch and puffiness (Table 4). This is a typical problem that occurs when the more vigorous varieties are cut at higher heights. Actually, the less vigorous varieties that have a reduced thatching tendency are generally preferred for turfs maintained at this higher height of cut. Seaside is one of the preferred varieties in this category followed by Astoria. Exeter and Highland have ranked at the bottom in most evaluations over the initial three growing seasons. Application Frequency of Tersan 1991 for Sclerotinia Dollar Spot Control. This study was initiated to determine if the normal spray interval of 10 to 14 days for a contact fungicide could be extended when the systemic fungicide Tersan 1991 is used. This data shows that the initial application of Tersan 1991 on May 8 at all rates tested held the dollar spot in check for approximately 2 months (Table 5). A second application was made on July 17 when some dollar spot symptoms began appearing in the Tersan 1991 plots. This second application controlled the dollar spot disease activity for an additional two months.

9 Table 4. BENTGRASS VARIETY EVALUATIONS FOR FAIRWAYS AND HIGH QUALITY LAWNS. East Lansing, Michigan Bentgrass Variety Toronto Eme raid Nr MSU-38-Ap Cohansey Kingston Pennpar Penncross MSU-18-Ap MSU-28-Ap Holfior Seaside Astoria Brabantia Boral Bt 806 Browntop Exeter Highland Visual Turfgrass Quality- Rating* (1 -Best: 9-Poorest) Average of six seasonal ratings. Table SCLERQTINIA DOLLAR SPOT CONTROL STUDY ON A TORONTO CREEPING BENTGRASS GREEN. East Lansing, Michigan Application Fungicide Rate Total number of spots Treatment oz/1000 sq.ft. 5/8*** 6/22 7/1*** 8/14 9/18 Tersan oz Tersan oz Tersan oz No Treatment 0 345** 460** 550** 600** Each figure is the total number of spots in 3 replications; the individual plot size was 8x8 feet or a total of 192 sq, ft. Estimation. Dates treatments were applied.

10 STOP 4 J. B. Beard Modifying the Turfgrass Environment The turfgrass microenvironment involves the conditions and influences immediately surrounding the turfgrass plant that effect growth and development. A significant aspect of turfgrass culture involves the manipulation of the turfgrass microenvironment in order to provide more favorable conditions for growth, development, and recuperation of the turf. Thus, it is important that turfmen have a good understanding of the microenvironment and also utilize procedures to periodically monitor certain aspects of the microenvironment so that they have a better basis on which to make decisions regarding turfgrass cultural practices. Soil moisture and temperature are the most easily monitored and modified components of the turfgrass microenvironment. Soil moisture levels can be monitored by use of a soil probe, electrical resistance sensors, or tensionmeters. Electrical resistance sensors are effective in measuring soil moisture in the moderately dry range, while the tensionmeter is more sensitive in moist to wet soil conditions typical of those found under intensely cultured turfs. The presence of a thatch or dense compacted soil surface interferes with successful use of tensionmeters. Both sensing devices are normally placed at a soil depth representative of the active turfgrass root zone usually between 2 and 6 inches. Temperature is also an important indicator in monitoring turfgrass growing conditions. Actually, the soil temperature in the upper 6 inches of the root zone is a far more reliable indicator of growing conditions than the air temperature. Several random samplings of soil temperature throughout a turfgrass area at varying depths can be readily made with a soil thermometer. They are available with sensing probes that reach to a depth of 6 to 10 inches, depending on the length of the probe. Continuous diurnal monitoring of soil temperatures at one or two given locations can also be achieved with a 7 day mechanical thermograph. The latter is preferred where documentation of seasonal temperature conditions on the turfgrass area are being maintained. This can be particularly helpful in locations where adequate weather bureau records are not available. Syringing. Temperature modification can be achieved through syringing. Investigations at M. S. U. show the time of syringing to be particularly important in achieving maximum temperature modification. Syringing for turfgrass cooling should be considered when soil temperatures approach 75 F. Where the objective is to modify temperature, the syringing application should be made between 11:00 a.m. and 12 noon. A syringing made at 1:00 to 2:00 has very little effect on the turfgrass temperature. However, syringing may be required between 12:00 noon and 2:00 p.m. should wilt occur since this is the period of highest evapotranspiration rates.

11 Winter Protection. Investigations at M. S. U. during the winters of and indicated that several materials can be effectively utilized as winter protection covers. Included were the Conwed Winter Protection Cover, Soil Retension Mat, Saran Shade (94%), and topdressing. The first three had superior performance in terms of desiccation prevention, low temperature insulation, and controlled early spring greenup. The topdressing practice is primarily effective in preventing winter desiccation. During the winter of a range of topdressing rates were evaluated. Included in the test were rates of 0. 1, 0. 2, 0. 3, 0. 4, 0. 5, 0. 6, 0. 7, and 0. 8 cubic yards per 1000 square feet. The soil was applied uniformily to the experimental area but not matted in. The study was conducted on 5 x 8 foot plots with three replications. Observations made during the winter and early spring period revealed the 0. 3 to 0. 4 cubic yard per 1000 square feet rate to be preferred in terms of protecting against winter desiccation without leaving an objectionable amount of soil on the surface which restricted spring greenup. It should be pointed out that the practice of topdressing is primarily effective in preventing winter desiccation and has no effect in reducing snow mold. Thus, it is important to apply the appropriate snow mold fungicide prior to making the topdressing application in late fall. STOP 5 J. E. Bogart, K. T. Payne, J. M. Vargas, and J. B. Beard Fine Leaved Fescued Variety Evaluations The red and chewings fescues are best adapted to shaded sites and droughty, sandy soils maintained at a minimal nitrogen fertility and irrigation level. Forty-five fine leaf fescue varieties were established September 13, 1968, for comparative evaluation under lawn-turf conditions. The plot size is 5 x 8 feet with 3 replications. The experimental area is cut at a height of 1. 2 inches twice per week with clippings returned. Irrigation is supplied as needed to prevent wilt. A split-plot nitrogen application has been made across the plots at rates of 2 and 4 lbs nitrogen per 1000 square feet per year. No fungicides or herbicides have been applied to the experimental area since establishment. C-26, a hard fescue has consistently ranked highest under conditions of this experiment (Table 5). This high level of performance can be contributed primarily to a higher level of He lm intho s p o r ium leaf spot resistance compared to the red and chewings fescues included in this study. Among the red fescues, which have a more creeping growth habit, Bergere, Brabantia, Arctared and S-59 have all ranked higher than Pennlawn red fescue.

12 TABLE FINE LEAF FESCUE VARIETY EVALUATIONS. East Lansing, Michigan Variety Festuca species Visual Turfgrass Quality Rating (1 -Best; 9-Po C-26 hard 2.6 Golfrood chewing s 2.7 Oregon K red 2.8 Wintergreen chewing s 2. 8 Bergere red 2. 8 Dawson chewing s 2.9 Barf alia chewing s 3. 0 Brabantia red 3.0 Highlight c he wings 3. 1 Arctared red 3. 1 Jame stown chewings 3.2 Erika chewing s 3. 3 Oregon D red 3.3 Sceempter red 3.4 S-59 red 3.4 Pennlawn red 3.5 Reptans red 3.5 Tjelvar red 3.6 Ruby red 3. 6 Polar chewings 3.7 BL- 127 chewings 3. 8 Casis chewings 3. 8 Cascade Dura turf chewings red Rubin red 4. 1 Illahee red 4.2 Steinacher red 4.2 Common chewings 4.3 Boreal red 4.3 Bargena red 4.4 Elco red 4.6 Rainier red 4.7 Clds red 4.7 Echo red 5.0 Cottage red 5. 1 Average of eight seasonal ratings.

13 The chewings fescues, those possessing a minimal creeping growth habit, that have ranked above Pennlawn include Golf rood, Winter green, Dawson, Barfalla, Highlight, Jamestown, and Erika. Thus, there are now a number of chewings and red fescues that are ranking above Pennlawn in general performance. Gf these, only C-26, Golf rood, Wintergreen, Highlight, and Jamestown are available commercially in North America. Several of these have been in seed production for only a limited period of time. Although there are a number of improved red and chewings fescues now available, none yet possess adequate levels of Helminthosporium leaf spot resistance to provide satisfactory lawns in monostands. However, some plant materials recently incorporated into the red fescue breeding program at M. S. U. show promise as being superior in terms of this characteristic as well as in creeping habit for good sod strength. Until these superior varieties are adequately tested and seed supplies are increased to levels where commercial marketing can be achieved, the best alternate practice is to blend several fine leaf fescues in order to take advantage of some of the preferred characteristics in each. Blending of Kentucky bluegrass varieties has proven desirable since no one variety has all the superior characteristics desired. Until recently, it has not been feasible to blend varieties of red fescue because of the lack of improved varieties available for use in the blend. However, a number of fine leaf fescue varieties are now available and can be combined in a blend to provide a wider genetic base in terms of adaptation and tolerance to turfgrass pests. STOP 6 K. T. Payne, J. B. Beard and J. M. Vargas Kentucky Bluegrass Variety and Blend Evaluations Kentucky bluegrass is best adapted to unshaded sites and moist, welldrained soils having a ph near neutral and a medium to high intensity of culture. Sixty-six Kentucky bluegrass varieties were planted September 13, 1968, in 4 x 6 foot plots with three replications. The experimental area is mowed twice a week at 1.2 inches with clippings returned. The area is irrigated as needed to prevent wilt. Sub-plot nitrogen treatments are made across the plots at 3 and 6 lbs of nitrogen per 1000 square feet per growing season. No herbicides or fungicides have been applied to the experimental area during the 1970 growing season. The 1970 evaluations for 26 commercially available Kentucky bluegrass varieties are included in Table 6. Nugget ranks superior to all other Kentucky bluegrass varieties included in this test, primarily because of superior resistance to both HeIminthosporium leaf spot and snow mold. Other varieties, in order of ranking, that were generally satisfactory during the season include Baron, Merion, A-34, Sodco, A-20, Fylking, Pennstar and A-10. Varieties which ranked decidedly inferior included South Dakota

14 Certified, PaJLouse, Delta, Arboretum, Troy, S-21, Kenblue and Geary. Excellent evaluations for He lm intho s po r ium leaf spot resistance were obtained during the 1970 growing season. Only Nugget ranked superior to Merion in this regard. Other varieties showing good leaf spot resistance included A-34, A-20, and Baron. These were followed by slightly lower rankings for Pennstar, Sodco, and Fylking. All other varieties possessed an objectionable degree of He Imintho s p o r ium leaf spot susceptibility and were seriously thinned to the extent that considerable weed invasion occurred. Snow mold damage to the Kentucky bluegrass varieties at East Lansing, was the most severe that had been observed in the past ten years. This permitted some reliable information to be collected concerning relative susceptibilities. Nugget and Baron demonstrated the least susceptibility to snow mold. Others showing very minimal snow mold injury included Merion, Sodco, Delta, A-34, Delft, Pennstar, and Campus. Varieties which were highly susceptible to Helminthosporium damage included Prato, South Dakota Certified, Kenblue, Cougar and Geary. The comparative evaluations for 38 additional Kentucky bluegrass varieties and selections are shown in Table 7. These varieties are not yet officially released for consumer utilization or are only available in Europe. Of these the NJE series from Rutgers University show excellent promise. Others ranking high include Belturf and Sydsport. A number of these varieties are being increased and will no doubt be released for consumer utilization within the next few years. Kentucky Bluegrass Blends Two studies concerning Kentucky bluegrass blend evaluations have been underway at East Lansing. Cne was established in 1962 and contained 11 different combinations of Merion, Newport, Park, Delta, and Kenblue. A second blend study was established in September of 1968, which included 11 different combinations of Merion, Newport, Park, Fylking, V/indsor, and Prato. Over this period the blends containing at least one Helminthospor ium leaf spot resistant variety were not significantly different in terms of visual turfgrass quality. The only time when the blends containing only leaf spot susceptible varieties ranked inferior was during the May-June period when leaf spot thinning was visually evident. Since no one Kentucky bluegrass variety ranks superior in all desired characteristics, it is desirable to combine three or four varieties which contain unique individual characteristics in terms of adaptation and disease resistance or appearance. The result is a turf that has better overall performance and adaptation to a range of soil and environmental conditions as well as a greater capability to persist under severe attacks from any one disease organism.

15 Table 6. Selection or Variety Nugget Baron Merion A-34 Sodco A-20 Fylking Pennstar A-10 Newport Captan Prato Delft Primo Windsor Campus Cougar Park Geary Kenblue 1970 KENTUCKY BLUEGRASS VARIETY EVALUATIONS* - East Lansing, Michigan He Imintho s po r ium Visual Turfgrass Quality Percent Snowmold leafspot susceptibility Rating*** Infestation (1-Best; 9-Poorest) 4/8/71 5/28/70 (1-Best; 9-Poorest) ** **

16 Table 6. (Continued) Helminthosporium Visual Turfgrass Quality Percent Snowmold leaf spot susceptibility Rating Selection Infestation (1-Best; 9-Poorest) or Variety 4/8/71 5/28/70 (1-Best; 9-Poorest) S Troy ** Arboretum ** Delta Palouse South Dakota Cert These varieties are commercially available. No data available. Average of eight seasonal ratings.

17 TABLE KENTUCKY BLUEGRASS VARIETY AND SELECTION EVALUATIONS* - East Lansing, Michigan Helminthosporium leaf spot susceptibility Visual Turfgrass Quality Rating** Selection (1-Best; 9-Poorest) (1-Best; 9-Poorest) or Variety 5/28/70 NJE P NJE P NJE P NJE P NJE P Belturf Sydsport NJE P WK-412 (Weibulls) Golf PSU-K WK N PSU-K NJE-P PSU-K WK N Ba PP Monopoly Spaths PSU-K PSU-K Zwartberg 7.0 4,4 Silve rblu Bar Atlas G Arista G Hunsballe Soma Minn WK Nike (continued on reverse side)

18 Table 7, (Continued) Helminthosporium leaf spot susceptibility Visual Turfgrass Quality Rating** Selection (1-Best; 9-Poorest) (1-Best; 9-Poorest) or Variety 5/28/70 Fusa SK Skandia II These varieties and selections are not generally available in Michigan. ** Ave rage of 8 seasonal ratings.

19 J. E. Kaufmann, K. T. Payne and J. B. Beard Winter Survival and Performance of 16 Perennial Ryegrass Varieties. The perennial ryegrass variety evaluation plots were established September 17, The plot size is 5 x 7 feet with three replications. The area is maintained at a cutting height of 1. 2 inches and is mowed twice per week with clippings returned. Irrigation is applied as needed to prevent wilt. Sub-plot nitrogen levels of 3 and 6 lbs. of nitrogen per 1000 square feet per year are maintained over the plots. No pesticides have been applied to the area during the 1970 growing season. The 1970 turfgrass quality evaluations for the 16 perennial ryegrasses may be seen in Table 8. Of the commercially available perennial ryegrass varieties, Manhattan has ranked superior followed by Pelo and Norlea. The main characteristics contributing to the superior ranking of Manhattan is its more diminutive, uniform growth habit, and improved mowing quality. Additional desirable factors are (a) a darker green color and (b) a slower vertical shoot growth rate, v/hich reduces the severity of competition with other desirable turfgrass species within the turfgrass community such as Kentucky bluegrass. The traditional problem with most perennial ryegrasses for turfgrass use has been the excessive vertical shoot growth rate which results in the species being too aggressive to remain compatible in a turfgrass stand with Kentucky bluegrass. In addition, perennial ryegrass has lacked low temperature hardiness for winter survival tinder Michigan conditions. The former characteristics has been minimized with the development of the more diminutive, low growing variety, Manhattan, which has a slower vertical shoot growth rate and improved compatibility with Kentucky bluegrass.. The combination of a diminutive perennial ryegrass variety with Kentucky bluegrass does offer a new alternative for seed mixtures to be utilized on sports turfs, Norlea ranks superior to all other commercially available perennial ryegrass varieties in terms of low temperature hardiness. Manhattan is intermediate in rank but is more hardy than most other available varieties. Ultimately, it would be desirable under Michigan conditions to have a variety possessing the characteristics of Manhattan plus even better low temperature survival so that ryegrass could persist on a long term basis within the turfgrass community. Among the experimental or European varieties included in this test Syn 0, Combi, and the MSU Diploid also possess improved low temperature hardiness. Syn 0 is one of the two selections which were combined to form the variety Manhattan.

20 TABLE PERENNIAL RYEGRASS VARIETY EVALUATIONS East Lansing, Michigan. Variety Winter Low Temperature Survival (1-Best; 9-Poorest) 4/22/71 Visual Quality Rating** (1-Best; 9-Poorest) Manhattan Syn 0* Pelo Norlea Brabantia* S-23* Combi* Bocage* MSU (Diploid)* Viris* Nr * NK Sceempter* Linn Ruanui* Ariki* Not commercially available in Michigan. Average of five seasonal ratings.

21 STOP 8 P. E. Rieke Sampling Turfgrass Soils Soil testing is a valuable tool in planning a turfgrass fertilization program. Sampling every 5 years on lawns will help to determine if any nutrient imbalance is developing. On more intensively managed turfs, such as golf greens, sampling every 2 to 3 years is useful. When establishing new turf or renovating a turfgrass area, soil testing is important for determining the need for lime and phosphorus which should be worked into the soil before establishment. As a turf manager becomes familiar with the soil, turfgrass conditions and fertilization program he can adjust this schedule accordingly. The soil test can be no better than the soil sample. Thus, it is important to obtain a representative sample. Soil can be sampled at any time the ground is not frozen, but care must be taken to avoid the first 2 or 3 weeks after fertilizing. The following steps are suggested for sampling turfgrass soils: 1. Use clean equipment to prevent contamination of the soil sample. 2. Use a soil probe or small garden tool to obtain 15 or 20 subsamples from the 0-2 inch depth. Combine these into one composite sample. If a problem area is to be tested, collect one composite sample from the problem area and a separate one from a normal area. 3. Mix each composite sample well. Allow to air-dry. 4. Record information as to the location of the sample (especially if more than one sample is to be tested). 5. Send about 1/2 pint of soil in a suitable container (preferably not glass) to your soil testing lab. Include any pertinent information which would help in interpretation, especially if a problem exists. 6. Keep the soil test results. They should be helpful in determining the success of your phosphorus and potassium fertilization program, especially for the professional turfman. Phosphorus and potassium fertilization should be based upon soil tests to avoid both inadequate and excessive applications. When soil test results are determined by the procedures used in the Michigan State University Soil Testing Laboratory, Tables 9 and 10 will serve as guides for determination of the desired rates of application. If more than 2 pounds of P2O5 is suggested per 1000 square feet on established turf, the fertilizer should be split into two or more applications. This is especially important for potassium fertilizers.

22 TABLE 9. PHOSPHATE (P205) APPLICATIONS BASED ON M. S. U. SOIL TEST. Soil Test General Turf Intensely Cultured Turfs* (lbs P/Acre) (Ibs/M) (lbs/acre) (lbs/m) Less than 25 (low) (medium) (high) Over 70 (very high) ^Includes golf greens. TABLE 10. POTASH (K20) APPLICATION BASED ON M. S. U. SOIL TEST. Soil Test General Turf Intensely Cultured Turfs* (lbs K/Acre) (lbs/m) (lbs /Ac re) (lbs/m) Less than 50 (low) (medium) (high) Over 250 (very high) ^Including golf greens and similar turf, especially on sandy soils with high irrigation rates.

23 A. J. Turgeon, W. F. Meggitt and J. B. Beard Effects of Repeated Applications of Preemergence Herbicide on Desirable Turfgrass Species. A study was initiated in 1964 to determine the effects of annual or biennial applications of eight peremergence herbicides on Kenblue and Merion Kentucky bluegrass and Pennlawn red fescue. The results have varied from year to year depending upon prevailing weather conditions and associated environmental stresses. Several trends have developed, however, which provide specific indications of the effects of these herbicides. Bandane has been moderately injurious to all three turfgrasses resulting in substantial thinning of the turf (Table 10), and severe stripe smut infestations on the Merion Kentucky bluegrass in the spring of 1970 and The red fescue plots treated with yearly applications of bandane were the most affected of the three turfgrasses as evidenced by the extensive transition from red fescue to Kentucky bluegrass in these plots. Red fescue was also significantly injured by DC PA, benefin, siduron and the arsenates. Evaluations in 1967 and 1969 revealed significant injury from bensulide on the two Kentucky bluegrasses but this has largely disappeared in recent years. Investigations are currently underway in which other effects of these herbicides will be ascertained. Root growth, thatch accumulation, carbohydrate reserves, and clipping weights are being measured to more accurately determine the effects of preemergence herbicides on these turfgrasses.

24 TABLE 10. EFFECTS OF REPEATED APPLICATIONS OF HERBICIDES ON THE QUALITY OF THREE TURFGRASSES. (Rating System: 1 = no effect, 9 = complete kill). Turfgrasse s Application Common Merion Pennlawn Trmt. Herbicide Rate Kentucky Kentucky Red No.* Treatment (lb/a) Bluegrass Bluegrass Fes ci 1 DCPA DCPA Lead arsenate Lead arsenate Bandane Bandane Terbutal Te rbutal Bensulide Bensulide Benefin Bene fin Calcium arsenate Calcium arsenate Siduron Siduron *A11 odd numbers treated yearly while all even numbers were treated every second year.